Mistral Research Lead Discusses Le Chonk: The Inside Story of the West's Largest Open Source Model Catching Up
Matt Turck speaks with Mistral research lead Pierre Stock about Le Chonk, described as the West's largest open source model. Stock discusses the team training on 3,800 GPUs in its own data center, the fact that Le Chonk is still in training, what Mistral borrowed from DeepSeek, and the trade-off between open-sourcing weights and refusal behavior for cybersecurity. The episode also mentions that Mistral Large 5 will be released later.
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Mistral's research lead gives an inside retrospective on the catch-up process, covering self-built training with 3,800 GPUs and the trade-offs of open-sourcing weights.
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Mistral is SO back: Inside Le Chonk, the West’s Biggest Open Model. My conversation with @PierreStock who runs the research organization at @MistralAI
0:00 Cold open 0:59 The Western open-weight comeback: Beam, Le Chonk, Muse, Nemotron 4:09 The US shutdown of Anthropic’s models - “AI is like electricity” 6:07 Why “Le Chonk” 7:56 “Mistral fell behind”: the comeback from the inside 10:29 Training on 3,800 GPUs in Mistral’s own datacenters 13:24 Meta keeps its best model closed, Mistral opens Chonk 15:40 Chonk vs Beam, Muse Spark Open and the Chinese models 18:44 Why Chinese labs are still at the frontier 21:08 Pierre’s story: FAIR, Yann LeCun, the “Mistral mafia” 25:14 From compressing networks to a trillion parameters 27:30 Mixture of experts explained: the hospital analogy 32:25 10-trillion-parameter models are coming 35:29 What Mistral borrowed from DeepSeek 36:46 One model, several reasoning modes 39:15 Native multimodality: satellites, manuals, computer use 41:56 Data, synthetic data and model collapse 46:32 Reinforcement learning as an exam 49:59 Where the efficiency comes from 52:18 Le Chonk is still training right now 53:39 What RL trains on: coding, cyber, finance, chips 58:13 Partial rewards and looping penalties 59:58 Did RL teach anything new? 1:03:16 The sandbox story: the model that pinged its trainer 1:07:44 Open weights vs cyber refusals 1:12:05 Timestral: time series on a CPU 1:14:18 AI doing AI research 1:16:22 Coming up: Mistral Large 5